In a vehicle front portion structure disclosed in JP-A No. H7-156666 listed below, an under cover is disposed in a front portion of a vehicle, and the under cover covers a front lower portion of the vehicle body. A cooling duct, a strake, and an air outlet are disposed at the under cover, and traveling wind is guided by the cooling duct, the strake, and the air outlet to a brake mechanism unit to cool the brake mechanism unit.